There are countless cases where major delays in product development are caused by poor estimation-related decisions. When it comes to both, high-level (long term features) and low-level (user stories, daily tasks) planning, developers tend to underestimate the work.
The retrospective aims to analyse what happened during the last sprint. We take into account people and interactions between them, the delivery process, tools and operational systems. Our approach to the process is holistic. It is from a distant perspective that we start to reflect and analyse the events relevant to the process.
Spotify grew tired of it and is trying to solve problems related to software development process. Luckily for us they are willing to share their conclusions.